The present invention relates to balers for making rectangular bales and more particularly relates to gear transmissions for driving various mechanisms of such balers.
One known baler drive includes a spiral bevel gear set which runs in an oil bath. The gear set driving gear is carried at the rear end of a fore-and-aft extending input shaft carrying a flywheel at its forward end, with power being delivered to the flywheel through means of a slip clutch. The gear set driven gear is mounted on a transverse output shaft having a crank formed therein and coupled for driving the baler plunger. The output shaft delivers power through a bevel gear set to further shaft and gear sets arranged for driving the baler feeder and knotter.
In U.S. Pat. No. 3,508,448 issued to Smith on 28 April 1970 there is disclosed a baler drive including a pair of concentric input shafts which are respectively adapted for connection for receiving power from a tractor PTO driven at either 540 rpm or 1,000 rpm. A flywheel is coupled for being driven at 1,000 rpm regardless of the tractor PTO speed. Therefore, the flywheel can be made smaller than it would otherwise have to be if rotated at 540 rpm by the tractor PTO.
The first prior art baler design discussed above has the disadvantages that (a) the flywheel is relatively heavy because its speed when driven by a tractor having a 540 rpm PTO speed is relatively slow, and (b) the spiral bevel gears are difficult to manufacture in the sizes necessary to carry the torque required for plunger operation. Both of these factors add to the expense of the drive.
The second prior art or patented baler design discussed above has the disadvantage that the concentric shaft and gearing arrangement is a relatively complex way to ensure that the flywheel operates at high speed and can thus be made relatively small.